Table 1.

Means, standard deviations and number of participants (n) for respiratory sinus arrhythmia (RSA), heart rate (HR1 at rest 1, HR2 at rest 2), skin conductance level (SCL) and non-specific skin conductance response (NS-SCR), by sex and zygosity

	Males		Females		DZ opposite sex
	MZ	DZ	MZ	DZ	Males	Females
Mean (Standard deviation)
RSA	.11 (.07)	.11 (.06)	.11 (.07)	.11 (.07)	.11 (.07)	.12 (.07)
N = 1,070	n = 240	n = 153	n = 242	n = 172	n = 127	n = 136
HR1	84.58 (11.97)	85.12 (9.55)	88.23 (11.90)	87.69 (11.54)	84.40 (11.81)	86.45 (10.94)
N = 1,078	n = 244	n = 155	n = 242	n = 174	n = 127	n = 136
HR2	82.27 (11.75)	83.34 (10.62)	86.48 (11.77)	86.52 (10.84)	81.89 (11.86)	84.67 (10.97)
N = 875	n = 197	n = 125	n = 203	n = 138	n = 105	n = 107
SCL	7.71 (4.51)	7.84 (4.08)	7.28 (4.56)	7.67 (4.22)	8.31 (4.66)	7.57 (3.54)
N = 1,133	n = 251	n = 158	n = 261	n = 184	n = 137	n = 142
NS-SCR	7.60 (8.15)	7.34 (7.33)	7.15 (8.32)	7.40 (7.64)	8.34 (7.80)	7.97 (6.91)
N = 1,069	n = 233	n = 143	n = 254	n = 171	n = 132	n = 136

MZ monozygotic, DZ dizygotic, N number of participants